1. Field of the Invention
This invention relates to a device for performing surgery particularly an ultrasonic scalpel wherein the scalpel is fully self-contained using batteries as a primary source of power with a switch to permit selection between cutting and cautery modes. When operated the ultrasonic scalpel has the ability for lateral motion as well as reciprocating motion of the scalpel blade causing tissue separation along interstitial margins.
2. Description of the Prior Art
In the prior art, it is well known that an ultrasonic surgery avoids the trauma, extensive scarring, and limitations of thermal cutting of electrosurgery and laser surgery. In ultrasonic surgery, the ultrasonic scalpel takes advantage of dissection technology as a result of oscillating motion of the blades. Ultrasonic energy is transmitted through a connection or mount between the ultrasonic energy source and a hand-held coupler which mounts the surgical tool, for example, a surgical blade mounted at the tip of the coupler. This connection facilitates transmission of ultrasonic motion from the energy source through the coupler to the surgical blade in order to generate vibrations in the blade in a reciprocating motion. This ultrasonic motion is then coupled with the tissue to which the blade is applied.
It was generally thought that the same sharp blades used with hand-held surgical scalpels should also be used with ultrasonic scalpels. It was discovered that in ultrasonic surgical instruments, duller blades achieved exceptional coagulation and cut better than by using sharp conventional scalpel blades. In fact, the duller blade greater transmission of ultrasonic energy is provided to adjoining tissue at the surgical site. This increased transmission was a result of increased blade cutting area in contact with the tissue. Better acoustic coupling as a result of greater transmission of ultrasonic energy enhances cutting capability and capacity for hemostatis. It was found, too, that grinding blades to reduce and modify cross-sectional area enhanced the harmonic xe2x80x9cwhipxe2x80x9d effect.
Existing ultrasonic scalpels can be applied to tissue with a vibrating reciprocating motion. While this reciprocating motion accompanied with dull blades has advantages over ultrasonic scalpels fitted with sharp blades, improved cutting with ease and quality can be achieved if there is lateral motion of the blades as well. Existing ultrasonic scalpels do not have the ability to achieve both ultrasonic lateral and reciprocating motion of the blade.
Existing ultrasonic scalpels also have the disadvantage of relying on external power supplies which connect to the surgical device by cord. Connection by cord to a power source can hamper portability of the scalpel as well as being cumbersome in some surgical operations.
Examples of prior art in this field include U.S. Pat. No. 4,587,958 entitled xe2x80x9cUltrasonic Surgical Devicexe2x80x9d issued to Noguchi et al. on May 13, 1986; U.S. Pat. No. 4,832,022 entitled xe2x80x9cCryogenic Ultrasonic Scalpelxe2x80x9d issued to Tjulkov et al. on May 23, 1989; U.S. Pat. No. 5,026,387 entitled xe2x80x9cMethod and Apparatus For Ultrasonic Surgical Cutting and Hemostatisxe2x80x9d issued to Thomas on Jun. 25, 1991; U.S. Pat. No. 5,167,725 entitled xe2x80x9cTitanium Alloy Blade Coupler Coated With Nickel-Chrome For Ultrasonic Scalpelxe2x80x9d issued to Clark et al. on Dec. 01, 1992; U.S. Pat. No. 5,254,082 entitled xe2x80x9cUltrasonic Surgical Scalpelxe2x80x9d issued to Takase on Oct. 19, 1993; U.S. Pat. No. 5,263,957 entitled xe2x80x9cUltrasonic Scalpel Blade and Methods of Applicationxe2x80x9d issued to Davison on Nov. 23, 1993; U.S. Pat. No. 5,324,299 entitled xe2x80x9cUltrasonic Scalpel Blade and Methods of Applicationxe2x80x9d issued to Davison et al. on Jun. 28, 1994; and U.S. Pat. No. 6,080,175 entitled xe2x80x9cSurgical Cutting Instrument and Method of Usexe2x80x9d issued to Hogendijk on Jun. 27, 2000.
It is therefore an object of the invention to provide an ultrasonic scalpel which imparts lateral harmonic motion to the blade and in addition reciprocating motion.
It is therefore a further object of the invention to provide an ultrasonic scalpel which can be used in improved cutting and dissection with ease and quality.
It is therefore a still further object of the invention to provide an ultrasonic scalpel which can be used in incising with superior subsequent wound healing and with minimization of scar tissue.
It is therefore a still further object of the invention to provide an ultrasonic scalpel which can effectively cauterize an incision with minimization of scar tissue.
It is therefore a still further object of the invention to provide an ultrasonic scalpel in a light, self-contained, hand held device thereby improving utility by weight and size advantages.
It is therefore a still further object of the invention to provide an ultrasonic scalpel which is disposable.
To attain the objects described, there is provided an ultrasonic scalpel ideally suited for minimally invasive surgery comprising a housing with a keyed cylinder and a blade coupler having a blade body and a shank extending from the blade body for coupling with a source of ultrasonic energy and transmitting the energy to the blade body. A transducer transmits ultrasonic energy to the blade causing both reciprocating and harmonic lateral motion of the blade. The ultrasonic energy transmitted from the transducer which causes harmonic lateral motion of the blade is due to an offset of approximately one half to two degrees between the drive of the transducer and the armature within the keyed cylinder. In addition the blade may also be subject to reciprocating motion.
The lateral harmonic motion produced is the reason for the ease and quality of a surgical cut and is the preferred embodiment of this invention. Improved cutting by enhanced tissue separation along interstitial margins is demonstrated. In the coagulation mode, the scalpel can operate at lower frequency and higher power providing thermal sealing. The proteinatious nature of tissue breakdown in the region surgerized at cutting frequency causes development of adherent surfaces leading to a coagulation effect. This coagulation effect enhances healing with a minimization of scar tissue.
The ultrasonic scalpel of this invention does not require the use of a power cord connected to an external source. A power cord in the close area of surgical operations can be cumbersome and hinder ease of movement of the ultrasonic scalpel. Instead, the power source of the scalpel is batteries in a section of the ultrasonic scalpel housing itself; however, there is capability for an external power source if needed. Also, the weight and size of other required parts of the ultrasonic scalpel such as the electrical actuator and the circuit components with transformer can be reduced. Since the entire ultrasonic scalpel could operate without a separate power supply, the unit is conceivable disposable.
These and other objects and characteristics of the present invention will become apparent from the further disclosure to be made in the detailed description given below.